docs: def _load_fsLR_atlasroi(filename, data):
      '''
      Loads the appropriate atlas for the given data; data may point to a cifti file whose atlas is
      needed or to an atlas file.
      '''
      (fdir, fnm) = os.path.split(filename)
      fparts = fnm.split('.')
      atl = fparts[-3]
      if atl in _load_fsLR_atlasroi.atlases: return _load_fsLR_atlasroi.atlases[atl]
      sid = data['id']
      fnm = [os.path.join(fdir, '%d.%s.atlasroi.%s.shape.gii' % (sid, h, atl))  for h in ('L', 'R')]
      if data['cifti']:
          dat = [{'id':data['id'], 'type':'property', 'name':'atlas', 'hemi':h} for h in data['hemi']]
      else:
          dat = [{'id':data['id'], 'type':'property', 'name':'atlas', 'hemi':(h + data['hemi'][2:])}
                 for h in ('lh','rh')]
      # loading an atlas file; this is easier
      rois = tuple([_load(f, d).astype('bool') for (f,d) in zip(fnm, dat)])
      # add these to the cache
      if atl != 'native': _load_fsLR_atlasroi.atlases[atl] = rois
      return rois